Can You Carry a Pocket Knife in the UK?

Yes. A pocket knife can be carried in a UK public place without a reason only if it meets two conditions together: a cutting edge of 3 inches (7.62cm) or less, and no locking mechanism.

Section 139 of the Criminal Justice Act 1988 makes it an offence to have a bladed or sharply pointed article with you in a public place. It then carves out one exemption in section 139(2) and (3) for a folding pocketknife ^[1]. This does not apply if the cutting edge of its blade exceeds 3 inches. Section 139 covers England and Wales. Section 172 extends it to Northern Ireland ^[6]. Scotland has its own near-identical offence in section 49 of the Criminal Law (Consolidation) (Scotland) Act 1995. There the exemption covers a folding pocketknife whose cutting edge “does not exceed three inches (7.62 centimetres)” ^[7]. Meet both parts of that test and no reason is needed. The knife needs good reason or lawful authority to carry if it misses either part. This happens through a longer blade or a locking mechanism.

The two-part test combines blade length with locking mechanism. This is the point most often misread by people who own an ordinary folding knife. This page sets out the rule, the defence, what police can do and the penalty.

The sections below explain the folding-pocketknife exemption, what counts as a public place, good reason, stop and search, school premises and penalties. They also address a knife forgotten in a bag.

What does the carrying offence actually cover?

Any article with a blade or a sharp point counts. Examples range from a kitchen knife to a craft blade. These are not just knives sold as weapons. The offence applies the moment the item is in a public place with the person. Intent does not matter.

“Public place” is defined broadly under section 139. It includes any place the public has access to, whether on payment or not. It covers streets, car parks, shops and public transport ^[1]. A knife left in a locked car parked on a private drive is different from the same knife carried into a supermarket. The exemption and the good-reason defence exist because this offence would otherwise catch huge numbers of ordinary tradespeople and knife owners going about daily life.

What is the folding-knife exemption exactly?

A folding knife is exempt from the carrying offence only if its cutting edge is 3 inches (7.62cm) or under and it does not lock open. Both conditions apply together. Neither applies alone.

The measurement runs along the cutting edge of the blade itself. It runs from the point where it meets the handle to the tip. It is not the full closed length of the knife. gov.uk confirms the exemption covers knives that “have a cutting edge no longer than 3 inches” and “are not lock knives” with “a button, spring or catch” ^[3]. A locking mechanism removes the exemption at any blade length. Full detail is on Lock Knives and UK Law.

Who has to prove good reason or lawful authority?

The person carrying the knife does. The prosecution does not. Section 139(4) frames good reason and lawful authority as a defence the accused must prove ^[1]. It is not something the police must disprove. In Scotland the equivalent defence is to show a reasonable excuse or lawful authority ^[7].

This shifts the practical risk onto anyone carrying a knife outside the automatic exemption. Accepted reasons include use at work, religious observance and national costume ^[3]. Full detail is on Good Reason to Carry a Knife: What UK Courts Accept. Carrying a knife because of a constant or ongoing threat is not a reasonable excuse, even where the threat is genuine. CPS guidance allows only a narrow exception for an imminent and specific attack ^[4].

Can police stop and search you for a knife?

Yes on reasonable suspicion. In England, Wales and Scotland this also applies without individual suspicion inside an area covered by a section 60 authorisation. Section 60 does not extend to Northern Ireland. Northern Ireland has separate police powers.

Section 60 of the Criminal Justice and Public Order Act 1994 lets an officer of inspector rank or above authorise stop and search in a locality for up to 24 hours. A superintendent can extend this for a further 24 hours where they reasonably believe serious violence may take place. It also applies where they believe people are carrying dangerous instruments or offensive weapons without good reason ^[8]. A uniformed constable can stop and search people for offensive weapons or dangerous instruments without individual suspicion inside that area and period ^[8]. The legislation.gov.uk text shows section 60 extends to England, Wales and Scotland ^[8].

What if you genuinely forgot the knife was there?

Forgetting alone does not count as a reasonable excuse. The Crown Prosecution Service is explicit that forgetfulness on its own is not a defence, even where the person is telling the truth about having forgotten.

The circumstances of how the knife came to be in a bag or car can occasionally support a good-reason argument. What happened next matters too. The fact of forgetting is not itself sufficient ^[4]. Someone who finds a knife left over from a legitimate use, such as work, stands on stronger ground if they take reasonably prompt steps to remove it. This is stronger than someone who simply says they forgot it was there.

Are the rules different on school premises?

Section 139A applies on school or further education premises to articles caught by section 139 and to offensive weapons. A non-locking folding pocketknife with a cutting edge of 3 inches (7.62 cm) or less is exempt from section 139 and is not caught by section 139A merely because it is on those premises ^[2].

For articles that section 139A does cover, a defence of good reason or lawful authority is available. It can include use at work, education, religious reasons or national costume ^[2]. Schools can ban knives under their own rules regardless of this criminal-law exemption. Other venues can set their own entry rules, and courts have security rules.

Does owning a knife at home carry the same restrictions?

No. Ownership at home is not covered by section 139 at all. The carrying offence only applies once the knife is with a person in a public place. It does not apply while the knife sits in a drawer, a toolbox or a display case at home.

This is why a locking knife or a large fixed blade can be bought, owned and kept at a private address without triggering the good-reason requirement. The same knife needs a specific reason the moment it leaves that private address with the owner. Banned knives are the exception to this. Items such as flick knives, zombie-style knives and machetes are restricted even in private. Full detail is on Banned Knives in the UK: The Full List.

Does it matter whether the knife is visible?

No. Visibility is not part of the test. The offence covers having the article with you, whether it is in a pocket, a bag, a vehicle or in plain view. Concealment is not what creates the offence. Openly carrying a knife that fails the exemption is not made lawful by carrying it visibly.

Some people assume that keeping a knife out of sight changes the legal position. Others assume carrying it openly to appear less suspicious changes it. Neither does. Two questions matter instead: whether the knife is folding, non-locking and 3 inches or under, and whether a good reason applies at that specific time when it does not.

What is the penalty for carrying a knife without good reason?

Up to 4 years in prison, a fine or both, on conviction on indictment in England, Wales and Northern Ireland. Scotland’s maximum is up to 5 years. Less serious cases are dealt with summarily. The maximum there is 12 months in all three jurisdictions.

In England and Wales the printed text of section 139(6)(a) still says six months on summary conviction ^[1]. Section 282 of the Criminal Justice Act 2003 has been in force since 2 May 2022. It reads that maximum as the general limit in a magistrates’ court for either-way offences ^[9]. Section 224(1A) of the Sentencing Act 2020 has set that limit at 12 months since 18 November 2024 ^[10]. The Northern Ireland version of section 139(6) states 12 months summary and 4 years on indictment directly ^[1]. Scotland’s section 49 sets 12 months summary and 5 years on indictment ^[7].

The Sentencing Council’s guideline sets category ranges. The least serious cases start at a low-level community order. These are cases where possession falls just short of a reasonable excuse. The most serious cases start at 1 year 6 months’ custody. Examples include offences involving schools or serious alarm and distress ^[5]. In England and Wales section 139(6ZA) points to section 315 of the Sentencing Code. This can require a minimum sentence for a person aged 16 or over with a previous relevant conviction ^[1].

This is legal information. It is not legal advice. Get advice from a solicitor or Citizens Advice for a specific situation.